Snakeskin or crocodileskin or starfishskin?
It might look similar but that is where the similarity ends. The 'last' of a starfish is made of this amazing substance which can change from being as hard as bone to as subtle as leather.
This starfish is a biscuit star, so named as their arms are so squat and close to the body you'd think it was all one structure.
Notice the strange plate with the little striations? Its the only plate like it on the the entire body of the starfish and it is the other of only two openings, the other being its mouth. This 'grate' allow the starfish to pass water and extract oxygen it without it it would drown.
Photo: Robert Rath, ‘Day 635, Starfishskin' 1/160s f/10 ISO320 100mm